Submitted to: National Fusarium Head Blight Forum Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 12/2/2007
Publication Date: 12/2/2007
Citation: Ding, S., Shou, X., Kistler, H.C., Xu, J. 2007. FMK1 Regulates the Expression of 333 Genes in Fusarium graminearum [abstract]. National Fusarium Head Blight Forum Proceedings. p. 25.
Technical Abstract: Fusarium graminearum is a devastating pathogen of wheat, barley, and maize throughout the world. The FMK1 gene encodes a well conserved MAP kinase that is essential for plant infection. To identify genes regulated by PMK1, in this study we conducted microarray experiments with the fmk1 mutant using the Fusarium graminearum Affimetrix GeneChip. In comparison with the wild-type strain, a total of 333 and 155 genes were down- and up-regulated ('2-fold), respectively, in the fmk1 mutant. Functional classification of the probe sets revealed multiple processes were affected by the deletion of FMK1. Many of these genes were unique to F. graminearum. Forty four of them encoded putative transcription factors with DNA-binding motifs. We selected 12 genes with altered expression levels in the pmk1 for verification by qRT-PCR. Four of the genes verified by qRT-PCR were functionally characterized. While two other genes appeared to be dispensable for growth and pathogenesis in F. graminearum, deletion of the ATG8 homolog and a putative Zn2Cys6 transcription factor significantly reduced its virulence on flowering wheat heads. The ATG8 homolog in Magnaporthe grisea also was down-regulated in the pmk1 mutant, suggesting that this MAP kinase pathway may have a regulatory role in authophagy. Our results also were useful to determine the transcription regulatory network controlled by this well conserved MAP kinase pathway for fungal development and pathogenesis.